Recorded in several forms including Selwood, Sellwood, Silwood and Sillwood, this is an English locational surname. It probably originates from Silwood Park, in the county of Berkshire, what is now known as a 'diminished' village, although Saltwood village in Kent is another, although faint, possibility. 'Diminished or 'lost' medieval villages are a feature of the surnames listings of the British Isles, and it is known that at least five thousand surnames do originate from these origins. 'Diminished villages' often occured when either the local lord of the manor decided that a village spoilt his view and he had most of it removed, or when the local agricultural systems changed, as for instance from arable to sheep farming. The result in both cases was that the tenants lost their homes and usually had little choice but to move elsewhere, taking or being given, as their surname, the name of their former home. Spelling being at best indifferent and local dialects very thick, often lead to the development of "sounds like" spellings. The development of this surname is encapsulated in the registers of the famous church of St Dunstans in the East, Stepney. The first recording there is believed to be that of Jone Selewood who married a John Curtis on May 18th 1589. The spelling remained as Selewood or Selwood until January 14th 1663 when John Sellwood was a christening witness, and then twenty years later we have further development when a John Sillwood is so recorded on April 14th 1682.